Physicochemical properties of galactomannans from Ceratonia siliqua and mayonnaise stability with purified LBG

Abstract

This work aimed to valorize carob by-products through the extraction and purification of locust bean gum (LBGc) The separation of carob seed components yielded 46.04% yellowish endosperm, from which 23.31% purified (LGBp) was obtained as a whitish powder. Physicochemical analysis exhibited that purification significantly increased the total sugar content (83.21 g/100 g) as well as the pH (6.82), while reducing the protein (0.22 g/100 g), lipid (0.20 g/100 g), ash (0.26 g/100 g), and fiber (0.09 g/100 g) contents compared to the LBGc. The hemolytic activity of LBGp was maintained low, with a maximum hemolysis of only 2.3% after 60 min at 10 mg/mL. Over the 60 days storage period, the three mayonnaise samples remained pH values between 3.2 and 3.5 and acidity between 3.9 and 5.1 g/100 g. Apparent viscosity values ranged from 14,875 to 330,000 cP, while the flow distance varied from 0.4 to 2.7 cm. Regarding stability, formulations containing either purified LGBp alone or modified starch alone exhibited structural degradation after 30 days of storage. In contrast, the formulation based on a mixture of purified locust bean gum and modified starch remained physically stable, with no phase separation observed even after 60 days.